Structure and use of fasteners having locking keys

ABSTRACT

A fastener including a threaded body to be connected to a coacting part, and a locking key received at least partially within a groove formed in the body, with the key being adapted to be driven generally axially relative to the body to a locking position, and with the groove being shaped to direct the key radially with respect to the axis of the thread and toward the material of the coacting part as the key advances generally axially, in a relation deforming the material of the coacting part by the key and thereby locking the thread against detachment from that part.

United States Patent N euschotz [451 Mar. 21, 1972 [54] STRUCTURE ANDUSE OF FASTENERS HAVING LOCKING KEYS [21] App]. No.: 798,686

2,608,123 8/1952 Israelson ..85/23 2,783,811 5/1957 Cummaro. l5l/4l.733,103,962 9/1963 Neuschotz l51/41.73 3,270,792 9/1966 Neuschotz et a1 l5 l [23 3,319,688 5/1967 Rosan et al... ..151/23 3,371,697 3/1968 James..151/23 Primary ExaminerMarion Parsons, Jr. Att0rneyWilliam P. Green 57I ABSTRACT A fastener including a threaded body to be connected to acoacting part, and a locking key received at least partially within agroove formed in the body, with the key being adapted to be drivengenerally axially relative to the body to a locking position, and withthe groove being shaped to direct the key radially with respect to theaxis of the thread and toward the material of the coacting part as thekey advances generally axially, in a relation deforming the material ofthe coacting part by the key and thereby locking the thread againstdetachment from that part.

12 Claims, 17 Drawing Figures 42 t I l l 28 23 23 T l9 5 '-l 2o PatentedMarch 21, 1972 3 Sheets-Sheet 2 .1. qua 5 lSa INVbNIOR fir-r oQlJEv '35I R0552? MEuscHoTz STRUCTURE AND USE OF FASTENERS HAVING.

LOCKING KEYS CROSS REFERENCES TO RELATED APPLICATIONS Certain featuresof the fasteners disclosed in the present application have been shownand claimed in my copending applications Ser. No. 688,563, filed Dec. 6,1967 entitled Lock Key Fastener Utilizing Deformed Thread As StopShoulder, now US. Pat. No. 3,435,870 Ser. No. 786,075 filed Dec. 23,1968 entitled Manufacture of Fastener Utilizing Deformed Thread As StopShoulder", and Ser. No. 798,659 filed Feb. [2, 1969 entitled FormationAnd Use Of Fasteners Having Keys".

BACKGROUND OF THE INVENTION This invention relates to threaded fastenersof a type having a locking key for retaining the fastener againstdetachment from a part to which it has been connected, with the keybeing driveable generally axially relative to the body of the fastenerto a locking position. The fastener is in most instances of a characterhaving two different threads or sets of threads, one of which isconnectable to the mentioned coacting part, while the other isconnectable to another part in a manner securing these two partstogether through the medium of the fastener. The invention will beillustrated and discussed primarily as applied to an insert device,having a generally tubular body with a first external thread and asecond internal thread, though it will be apparent that the invention isalso applicable to other fastener structures, such as stud arrangementsin which two external threads are utilized.

In my US. Pat. No. 2,855,970 issued Oct. I4, 1958,] have shown a type ofthreaded fastener having axially driveable locking keys which in somerespects are similar to the keys of the present invention. The keysutilized in that prior patent are carried within grooves in the fastenerbody, and have a first relatively thin mounting portion received withinthe groove, and a thicker locking portion which projects radiallyoutwardly far enough to cut through and deform the material ofa coactingthreaded part when the key is driven axially, to thereby lock thefastener against detachment from that part. The thickened lockingportion desirably serves also the secondary function of engaging thecoacting threaded part, upon initial connection of the fastener bodythereto, in a manner limiting the extent to which these parts may bescrewed together, to thus accurately predetermine the positioning of thethreaded parts relative to one another. In my copending applicationsSer. No. 688,563 now US. Pat. No. 3,435,870 and Ser. No. 786,075, I haveshown arrangements in which means other than the locking keys themselvesmay be utilized for attaining this secondary relative positioningfunction of the keys.

SUMMARY OF THE INVENTION A major purpose of the present invention is toprovide a new type of fastener structure having a locking key which isdriveable generally axially to its locking position as discussed above,but in which the key need not be designed to have the mentionedthickened portion in order to attain an effective locking action, thoughthe invention is of course not to be understood as precluding use ofsuch a thickened portion if desired in conjunction with or as asupplement to the locking action taught in the application. In itssimplest form, the key of the present invention may be much less complexin configuration than the keys of my US. Pat. No. 2,855,970, and may becorrespondingly much less expensive to manufacture, less critical toinstall, and less critical to dimension during manufacture.

To attain these results, I so form the groove within which the lockingkey is received that, as the key is driven generally axially, the groovecauses the key to also advance in a radial direction, so that thisradial movement forces the advancing key into the material of thecoacting part, to deform or cut through that material in a mannerattaining a very effective locking action for retaining the partsagainst threaded detachment. In one form of the invention, the mountinggroove has a wall which curves gradually and smoothly in a radialdirection as it advances axially, and the key is sufficiently deformableto follow the curvature of that groove and be guided thereby into thematerial of the threaded part, and preferably into the threads of thatpart. In another arrangement, the key is initially disposed at an angledirecting it into the material of the carrier part without bending. Formaximum simplicity, the groove is in either instance initially formed toa non-undercut cross section, with the key being adapted to itselfdistort or cut the groove to a slightly undercut cross section as thekey is driven into and within the groove, so that this undercut sectionserves to retain the key against radial separation from the groove,without the necessity for a secondary machining operation to undercutthe groove prior to installation of the key.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features andobjects of the invention will be better understood from the followingdetailed description of the typical embodiments illustrated in theaccompanying drawings, in which:

FIG. 1 is an axial section through a threaded insert formed inaccordance with the invention, and shown positioned within a carrierpart, with the keys illustrated as they appear prior to being drivenaxially to their locking positions;

FIG. 2 is a view similar to FIG. 1 but showing one of the keys afterhaving been driven to locking position;

FIG. 2a is a perspectiverepresentation of one of the locking keys ofFIGS. 1 and 2;

FIG. 3 is an enlarged fragmentary side view of the insert, takenessentially on line 3-3 of FIG. 1, without showing the carrier part;

FIGS. 4, 5 and 6 are transverse sections taken on lines 4-4, 5-5 and 6-6respectively of FIG. 3;

FIG. 7 is a perspective view of a variational type of key;

FIG. 8 is a view similar to FIG. 3 but utilizing the FIG. 7 type of key;

FIG. 9 is a side view ofthe key of FIGS. 7 and 8;

FIG. 10 is a section taken on line 10-10 of FIG. 9;

FIG. 11 is a view similar to FIG. 2 showing a variational type of keyarrangement, with the key illustrated in full lines as it appears beforebeing driven to its locking position;

FIGS. 12 and 13 are transverse sections taken on lines 12- 12 and 13-13respectively of FIG. 11;

FIG. 14 is a view similar to FIG. 13 but showing a variational type ofkey cross section;

FIG. 15 is a view similar to FIG. 11, but showing still another form ofthe invention; and

FIG. 16 shows the manner in which the keys of FIG. 15 may be driven totheir locking positions by a special driving tool.

DESCRIPTION OF THE PREFERRED EMBODIMENTS There is shown in FIG. I athreaded insert assembly 10 as it appears when screwed into a carrierpart 11, to a position in which the insert is to be locked within thecarrier part. The insert assembly includes an essentially tubular insertbody 12 carrying one or more locking keys l3, typically two such keyspositioned at diametrically opposite locations with respect to the axis14 of the tubular body 12. The carrier part may be formed of anyappropriate material, such as aluminum, steel, another metal, a resinousplastic material, or the like. The carrier part contains a passage 15within which the insert is received, and having internal threads 16centered about axis 14. A tapering frustoconical annular countersinksurface 17, centered about axis 14, is formed in the carrier part at theaxially outer end of thread 16, adjacent a typically planar outersurface 18 of the carrier part disposed transversely of axis 14.

Insert body 12 is formed of an appropriate rigid material, usually steelor another rigid metal, and has an external thread 19 centered aboutaxis 14 and dimensioned to mate with internal thread 16 of the carrierpart. Preferably, both of these threads 16 and 19 are of standard 60degree configuration except as to their minor diameters, at whichcylindrical modified minor diameter surfaces 20 and 21 may be provided,which surfaces have a greater diameter and greater axial extent thanthey would have if thethreads were completely standard in shape anddimension. Internally, insert body 12 has a second thread 22, concentricwith threads 16 and 19 and centered about axis 14, and into which ascrew, stud or other externally threaded part may be connected, tosecure that part to the carrier part 11 through the medium of the insertassembly. Threads 22 may be completely standard in configuration anddimension.

At the time of manufacture of the insert assembly 10, the two keys 13are driven partially into diametrically opposite mounting grooves 23formed in the outer surface of body 12,

and are frictionally retained in the FIG..1 positions of partial 7reception within those grooves during handling of the insert assemblyprior to installation, so that the body 12 and keys 13 may be handled asa single effectively integral unit prior to and during installation.Each groove 23 as initially machined is preferably of a non-undercutcross section, such as that illustrated in FIG. 6, being defined at itsopposite sides by two parallel planar opposite side wall surfaces 24which lie in planes disposed parallel to axis 14 of the insert, andspaced equal distances from the axis, and from a radial planeillustrated at 25 in FIG. 6 which extends through and contains axis 14.At its radially inner side, each groove 23 has an inner wall surface 26which faces radially outwardly. From the axially outer extremity 27 ofthe groove (FIG. 1), to the location designated 28 in FIG. 1, the innerwall 26 of the groove may be planar and extend directly parallel to axis14, and perpendicular to the radial plane 25 of FIG. 6. Also, inextending between the locations 27 and 28, inner wall 26 of the groovemay be located radially inwardly of the diameter of minor diametersurfaces 21 of thread 19, far enough to enable reception of key 13inwardly of the minor diameter of the internal thread within the carrierpart 11, so that the insert assembly can be screwed to the FIG. 1position within the carrier part without interference being afforded byengagement of the keys with the carrier part thread.

Downwardly or axially inwardly beyond the location 28 of FIG. I, theinner wall 26 of each groove 23 curves gradually and smoothly radiallyoutwardly at 29, and after curving outwardly to an increased diametermay then curve gradually and smoothly to a more axially extendingcondition. The groove 23 thus extends axially through, and interrupts,the external thread 19 of the insert body, preferably through the entireaxial extent of that body.

In accordance with the teachings of my copending application Ser. No.798,659, the keys 13 are desirably so formed as to themselves deform theinitially non-undercut grooves 23 to undercut cross section as the keysare driven into the grooves during assembly of the insert structure. Forthis purpose, each key may have an axially inner portion 32 (FIGS. 2aand 3) having two laterally projecting elongated fins 33 at its oppositesides, of a width slightly greater than the width w between the oppositeside wall surfaces 24 ofthe groove. As seen in FIG. 5, these fins arelocated adjacent the planar undersurface 34 of portion 32 of the key,which surface engages and slides along inner wall surface 26 of thegroove, with lateral continuations of undersurface 34 typically formingthe undersurfaces of the fins at 34. The upper surfaces 35 of the finsmay advance gradually and progressively toward the plane of surface 34as they advance laterally, as viewed in FIG. 5.

The fins 33 of key 13 may continue from the axially inner end 36 of thekey to the location 37 of FIG. 3, with the fins and keys desirably beingof uniform and unchanging cross section through the entire axialdistance between these points. Upwardly or axially outwardly beyond thelocation 37, the key may have the rectangular cross section illustratedin FIG. 4, and may define a portion 38 of the key which projectsupwardly from and beyond the groove, and beyond the upper transverse endsurface 39 of the tubular insert body 12, for engagement by a drivingtool to drive the key axially downwardly to its locking position. Aswill be apparent, the entire key may initially be formed of a simpleflat strip of metal having the cross section illustrated in FIG. 4, withthat cross section being forged to the FIG. 5 condition downwardlybeyond the location 37 of FIG. 3. The effective thickness I of the key(FIG. 1) is thus essentially uniform along the entire length of the key,except as altered by provision of the fins, with that thickness beingsmall enough for the previously mentioned reception within the minordiameter of the carrier part threads, and with that thickness preferablybeing approximately equal to the depth d of the associated groove 23inwardly beyond the minor diameter ofthread 19 (FIG. 6).

In assembling the keys 13 to insert body 12, these keys are drivenaxially inwardly into grooves 23, to the position of FIGS. 1 and 3, sothat fins 33 of the key act to deform the initially non-undercut groove23 to the undercut configuration of FIG. 5, which configuration acts toeffectively confine the key against radially outward separation orremoval from the groove. Also, such driving of the key into the groovecauses the insert body to tightly frictionally hold the keys in the FIG.1 positions with respect to the body, during handling and installationof the assembly. The undercut guideway recesses 39 formed in theopposite side walls 24 of each groove by fins 33 of course continuedownwardly or axially inwardly only so far as the axially innerextremities of the fins are driven, that is to the locations 40 in FIG.3. Axially inwardly beyond that location, each groove retains itsoriginal non-undercut cross section, as will be apparent from FIG. 6.

At the time of installation of the insert assembly into the carrier part11 of FIG. 1, external thread 19 of insert body 12 is screwed into theinternal thread 16 of the carrier part until the insert body reaches theFIG. I position, in which its outer end surface 39 is approximatelyflush with outer surface 18 of the carrier part, and preferably is in aslightly underflush position with respect to surface 18. In order tolimit the advancement of the insert body into the carrier part at thisFIG. 1 position, I preferably deform the uppermost or axially outermostturn 41 of external thread 19 axially inwardly, to the cross sectionillustrated in the left-hand portion of FIGS. 1 and 2, so that theundersurface 42 of this turn of the thread functions as a stop shoulderadapted to engage countersink surface 17 and halt axial advancement ofthe insert body at the FIG. I position. More particularly, as seen inthe left-hand portion of FIG. 3, this upper end turn 41 of the threadmay be deformed to a position in which it advances essentiallycircularly about axis 14, rather than helically. Two ways in which thisend turn may be deformed to attain the discussed motion limitingfunction are covered in greater detail in my applications Ser. Nos.688,563 and 786,075 and consequently no further elaboration on thestructure of this deformed thread will be included in the presentapplication.

To now describe in detail the process of installing the insert assembly10 within carrier part 11, assume first of all that the body 12,carrying keys [3, is screwed into the carrier part to the FIG. Iposition, with the advancement being halted at that position by thediscussed engagement of deformed portion 41 of external thread 19 withcountersink 17. After the insert assembly has reached this FIG. 1position, a user drives keys 13 axially inwardly, with a hammer or otherdriving tool, from the FIG. 1 position to the FIG. 2 position of thekeys. As each key advances axially inwardly, it is cammed radiallyoutwardly by the curving inner wall surface 26 of the coacting groove23, to cut through and deform the threads of the carrier part, and thusform an effective interlock preventing unscrewing rotation of the insertbody 12. During advancement of the keys relative to the insert body, thefins 33 form continuations of the guideway recesses 39' of FIG. 5. Ifdesired, the outward curvature of groove walls 26 may be more gradualthan illustrated in FIGS. 1 and 2, so that there is no necessity for thereverse curving of the insert to its more axially extending condition asindicated in the lower portion of FIG. 2. The keys I3 are of courseformed of a material which is capable of bending as indicated, to enablethe discussed outward deflection along the camming surface 26. Anappropriate slightly deformable but relatively stiff spring steel orother metal will serve this purpose.

FIGS. 7 through 10 show another form of key which may be substituted forthat shown in FIGS. 1 through 6, and in which instead of the singleelongated pair of fins 33, there are provided two axially spaced pairsof laterally projecting fins 33a, formed on the axially inner portion32a of each key 13a. These fins may have planar undersurfaces 134aaligned with and forming continuations of the planar undersurface 34a ofthe main body of the key, and may have upper camming surfaces 350 asthey advance axially inwardly (downwardly in FIG. 9), to cam the keyagainst the inner wall 260 of the associated groove 23a as the key isinitially driven into the groove, and as it is subsequently driven toits locking position. The outer edges 135 of fins 33a may convergeprogressively toward one another as they advance axially inwardly, tofacilitate the formation of undercut guideway recesses corresponding tothose shown at 391 in FIG. 5. The key 13a is installed within an insertin the same manner discussed in connection with the first form of key,and is subsequently driven axially to a position such as thatillustrated in FIG. 2 to cut through the threads of the carrier part,and lock the fastener assembly against removal from that part.

FIGS. 11 through 13 illustrate fragmentarily another form of theinvention, in which one or more keys 13b (desirably two diametricallyopposite keys) are mounted within two generally axial grooves 23b formedin the outer surface of insert body 12b, in a manner very similar to thearrangement of FIG. 1, but with the keys being disposed at a slightangle a with respect to the axis 14b of the insert, rather thanextending directly axially as in FIG. 1. Each key 13b of FIGS. 11through 13 may typically be of substantially the same construction asthe FIG. 1 keys 13, having an axially outwardly projecting portion 38bof rectangular cross section (corresponding to the cross section of FIG.4), and an axially inner mounting portion 32b of the FIG. 5 crosssection frictionally retained and confined within groove 23b. Theradially inner wall 26b of the groove may be planar and straight alongits entire extent, and be disposed at the previously mentioned angle awith respect to axis 14b of the insert and its internal and externalthreads, so that the key is effectively guided for straight linemovement axially inwardly from the full line position of FIG. 11 to thebroken line position of that figure. The opposite side wall surfaces 24bof the groove are initially planar and parallel, in correspondence withsurfaces 24 of FIG. 6, and are deformed by the fins 33b of the key tothe undercut or dovetail cross section illustrated in FIG, 13, when thekey is driven into the groove to the FIG. 11 full line position. In thatposition, the mounting portion 32b of the key is received radiallyinwardly of the minor diameters of external threads 19b on the insert,and internal threads 1611 within the carrier part 11b. As the key isdriven axially inwardly to its broken line position, the key advancesradially outwardly beyond the minor diameters of threads 16b and 19b, tocut through the internal threads 1612 within the carrier part, andthereby lock the insert against unscrewing rotation relative to thecarrier part. This locking action is attained without the necessity forbending ofthe keys as is required in the FIG. 1 arrangement.

FIG. I4 is a view similar to FIG. 13, but showing a key 13c of slightlydifferent cross section, in which the fins 330 are spaced slightlyradially outwardly beyond the plane of the radially inner surface 34c ofthe key, and the engaged inner wall 266 of the groove. Also, the key ofFIG. 14 has a cross section which more nearly approaches a squaresection than does the relatively elongated rectangular cross section ofthe FIG. 13 key. As will be apparent, any of numerous othercrosssectional configurations may be given to the key and its fins, solong as the key is preferably effective to convert the groove from anon'undercut cross section to an undercut cross section when the key isdriven into the groove.

FIG. 15 shows another variational arrangement which may be considered asidentical with that of FIG. 11 except that the fins 33d of the key 13dare somewhat different, and the axially outwardly projecting drivingportion 38d of the key is bent at 138 to extend directly parallel to theaxis 14b of the insert and its threads, rather than at the angle 00 ofthe remainder of the key. The key may be initially straight at the timeof installation, with portion 38d being bent to its axially extendingposition after the key has been driven into groove 23d. As will beapparent, the key is easier to drive by a hammer or other driving toolwhen its outwardly projecting portion extends directly axially, and canbe driven with less chance of unwanted bending or distortion of the keyduring driving. The bent portion 38d of course tends to follow thefinned leading portion of the key as the key is driven to its lockingposition, so that in that locking position the key assumes a straighterconfiguration than illustrated in FIG. 15. Fins 33d of FIG. 15 aretypically il- -lustrated as including two axially spaced pairs of suchfins,

with these fins being disposed at a slight camming angle with respect tothe inner wall 26d of groove 23d, and the planar inner surface 34d ofthe finned portion of the key. The camming angularity serves the purposeof the angularity of surface 35a in FIG. 9, to tend to urge the keytightly against surface 26d at all times during initial installation ofthe key, and subsequent movement of the key axially inwardly to itslocking position.

FIG. 16 shows the insert 10d of FIGS. 11 through 13, in conjunction witha special tool 43 for driving the keys to their locking positions. Thistool has a first rigid pilot element 44, having an outer cylindricalsurface 45 centered about axis 14b of the insert, and having an annularcamming surface 46 at its leading end centered about axis 14b. Surface46 tapers radially inwardly to a diameter less than the spacing sbetween the uppermost ends of the two diametrically opposed keys 13b intheir FIG. 11 normal angularly disposed positions, so that when thelower tapered end of element 44 is pushed downwardly between theangularly disposed upper ends of the keys, it will deflect or cam thekeys laterally to the parallel axially extending full line positions ofFIG. 16. The diameter of outer cylinder surface 45 of element 44 shouldbe such as to maintain the keys in this described directly axiallyprojecting position when element 44 is in its FIG. 16 installingposition.

At its axially outer end, element 44 carries a transverse diametricalpin 46', whose opposite ends project into parallel axial slots 47 formedin the cylindrical side wall 48 of a driving element 49, the latterhaving a transverse axially outer end surface 50 to be engaged by ahammer or other driving tool at the time of actuation of the keys totheir locking positions. A coil spring 51 may normally urge element 49axially outwardly to its FIG. 16 position relative to element 44. Theannular axially inner transverse end surface 51 of portion 48 of element49 is ofa diameter to engage the axially outer ends of the two keys intheir FIG. 16 full line positions, so that when element 49 is drivendownwardly or axially inwardly it functions to drive the keys to theirbroken line locking positions of FIG. 11.

In installing an insert of the FIG. 11 type with the tool of FIG. 16,the first step is to screw the insert to its FIG. 16 position within thecarrier part, with the outwardly projecting ends of the keys beinghelpful in turning the insert to that position. Next, a user moves tool43 axially inwardly to the FIG. 16 position, so that camming surface 46engages the angular keys and deflects their outwardly projecting endslaterally and apart to the full line positions of FIG. 16, followingwhich element 49 is driven axially inwardly relative to element 44 todrive the keys to their locking positions.

In all of the discussed forms of the invention, it will of course beapparent that the key retaining grooves may if While I have typicallydescribed certain specific embodiments of my invention, it is of courseto be understood that the invention is not limited to these particularforms, but rather is applicable broadly to numerous variations fallingwithin the scope of the appended claims.

lclaim:

1. A fastener assembly comprising a body having a thread which isdisposed about an axis and is adapted to be connected to a coactingpart, said body containing a generally axially extending groove, a keyreceived at least partially within said groove and adapted to be drivengenerally axially therein to a locking position, said groove beingshaped to direct said key along a path which advances radially towardthe material of said coacting part as the key advances generallyaxially, in a relation deforming said material of the coacting part bysaid key and thereby locking said thread against detachment from thecoacting part, said groove having a portion of undercut cross sectioncontaining andretaining a portion of said key, said groove having asecond portion axially inwardly beyond said first mentioned portionwhich is of non-undercut cross section until the key is driven axially.

2. A fastener assembly comprising a body having an external thread whichis disposed about an axis and is adapted to be screwed into an internalthread in a carrier part, and having an additional thread to beconnected to another member to secure the latter to the carrier partthrough the medium of said body, said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread, a key received at least partially within said grooveand adapted to be driven generally axially therein to a lockingposition, said key having a portion positioned in the groove deep enoughto advance within the interior of said internal thread in the carrierpart without substantial interference therewith, and said groove beingshaped to direct said portion of the key radially outwardly into saidinternal thread of the carrier part as the key is driven generallyaxially to thereby deform the internal thread and lock said body againstdetachment from the carrier part, said groove having a first portion ofundercut cross section containing said key and retaining it againstradial separation from the groove, and having a second portion ofnon-undercut cross section beyond said first portion of the groove andadapted to be deformed to an undercut cross section by the key as it isdriven generally axially.

3. A fastener assembly as recited in claim 2, in which said key has finsat its opposite sides for deforming said groove to said undercut crosssection.

4. A fastener assembly as recited in claim 2, in which said key has finsat its opposite sides for deforming said groove to said undercut crosssection, said fins having a camming shape tending to urge said keytightly against an inner wall of the groove as the key advancesgenerally axially.

5. A fastener assembly comprising a body having an external thread whichis disposed about an axis and is adapted to be screwed into an internalthread in a carrier part, and having an additional thread to beconnected to another member to secure the latter to the carrier partthrough the medium of said body; said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread; a key having a first portion tightly retained in fixedposition within an undercut portion of said groove, to remain in saidfixed position as said body is screwed into a carrier part, and adaptedto be driven thereafter generally axially to a locking position; saidfirst portion of the key being carried in the groove at a location deepenough to advance within the interior of said internal thread in thecarrier part without substantial interference therewith as said body andthe carried key are screwed into the carrier part, said key having asecond portion projecting axially outwardly beyond the groove andaccessible for driving the key axially inwardly to said locking positionafter the body and key have been screwed into said carrier part; andsaid groove being shaped to direct said first portion of the keyradially outwardly into said internal thread of the carrier part as thekey is driven generally axially to said locking position and in arelation deforming the internal thread and locking said body againstdetachment from the carrier part, said groove being disposed at an angleto said axis, said first portion of the key received within the groovebeing disposed at said angle to the axis, and said second portion whichprojects axially outwardly beyond the groove being disposedsubstantially parallel to said axis.

6. A fastener assembly comprising a body having an external thread whichis disposed about an axis and is adapted to be screwed into an internalthread in a carrier part, and having an additional thread to beconnected to another member to secure the latter to the carrier partthrough the medium of said body; said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread; a key having a first portion tightly retained in fixedposition within an undercut portion of said groove, to remain in saidfixed position as said body is screwed into a carrier part, and adaptedto be driven thereafter generally axially to a locking position; saidfirst portion of the key being carried in the groove at a location deepenough to advance within the interior of said internal thread in thecarrier part without substantial interference therewith as said body andthe carried key are screwed into the carrier part, said key having asecond portion projecting axially outwardly beyond the groove andaccessible for driving the key axially inwardly to said locking positionafter the body and key have been screwed into said carrier part; andsaid groove being shaped to direct said first portion of the keyradially outwardly into said internal thread of the carrier part as thekey is driven generally axially to said locking position and in arelation deforming the internal thread and locking said body againstdetachment from the carrier part, said key being shaped to deform thegroove from a non-undercut cross section to an undercut cross section asthe key is driven generally axially, and having a camming shape tendingto urge the key radially against an inner wall of the groove during andas a result of said generally axial movement.

7. A fastener assembly comprising a body having an external thread whichis disposed about an axis and is adapted to be screwed into an internalthread in a carrier part, and having an additional thread to beconnected to another member to secure the latter to the carrier partthrough the medium of said body; said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread; a key having a first portion tightly retained in fixedposition within said groove, to remain in said fixed position as saidbody is screwed into a carrier part, and adapted to be driven thereaftergenerally axially to a locking position; said first portion of the keybeing carried in the groove at a location deep enough to advance withinthe interior of said internal thread in the carrier part withoutsubstantial interference therewith as said body and the carried key arescrewed into the carrier part, said key having a second portionprojecting axially outwardly beyond the groove and accessible fordriving the key axially inwardly to said locking position after the bodyand key have been screwed into said carrier part; and said groove beingshaped to direct said first portion of the key radially outwardly intosaid internal thread of the carrier part as the key is driven generallyaxially to said locking position and in a relation deforming theinternal thread and locking said body against detachment from thecarrier part, said groove having a first portion of undercut crosssection containing said key and retaining it against radial separationfrom the groove, and having a second portion of non-undercut crosssection beyond said first portion of the groove and adapted to bedeformed to an undercut cross section by the key as it is drivengenerally axially.

8. A fastener assembly as recited in claim 7, in which said key has finsat its opposite sides for deforming said groove to said undercut crosssection, said fins having a camming shape tending to urge said keytightly against an inner wall of the groove as the key advancesgenerally axially.

9. A fastener assembly as recited in claim 7, in which said groove has aradially inner wall against which said key is received and which inadvancing axially inwardly first extends substantially directly axiallyat a location spaced inwardly of the minor diameter of said externalthread and then curves smoothly and gradually radially outwardly todeflect the key into said thread of the carrier part.

10. A fastener assembly as recited in claim 7, in which said groove isdisposed at an angle to said axis to direct the key at a radiallyoutward angle; said first portion of the key which is retained in fixedposition within said groove, being disposed at

1. A fastener assembly comprising a body having a thread which isdisposed about an axis and is adapted to be connected to a coactingpart, said body containing a generally axially extending groove, a keyreceived at least partially within said groove and adapted to be drivengenerally axially therein to a locking position, said groove beingshaped to direct said key along a path which advances radially towardthe material of said coacting part as the key advances generallyaxially, in a relation deforming said material of the coacting part bysaid key and thereby locking said thread against detachment from thecoacting part, said groove having a portion of undercut cross sectioncontaining and retaining a portion of said key, said groove having asecond portion axially inwardly beyond said first mentioned portionwhich is of non-undercut cross section until the key is driven axially.2. A fastener assembly comprising a body having an external thread whichis disposed about an axis and is adapted to be screwed into an internalthread in a carrier part, and having an additional thread to beconnected to another member to secure the latter to the carrier partthrough the medium of said body, said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread, a key received at least partially within said grooveand adapted to be driven generally axially therein to a lockingposition, said key having a portion positioned in the groove deep enoughto advance within the interior of said internal thread in the carrierpart without substantial interference therewith, and said groove beingshaped to direct said portion of the key radially outwardly into saidinternal thread of the carrier part as the key is driven generallyaxially to thereby deform the internal thread and lock said body againstdetachment from the carrier part, said groove having a first portion ofundercut cross section containing said key and retaining it againstradial separation from the groove, and having a second portion ofnon-undercut cross section beyond said first portion of the groove andadapted to be deformed to an undercut cross section by the key as it isdriven generally axially.
 3. A fastener assembly as recited in claim 2,in which said key has fins at its opposite sides for deforming saidgroove to said undercut cross section.
 4. A fastener assembly as recitedin claim 2, in which said key has fins at its opposite sides fordeforming said groove to said undercut cross section, said fins having acamming shape tending to urge said key tightly against an inner wall ofthe groove as the key advances generally axially.
 5. A fastener assemblycomprising a body having an external thread which is disposed about anaxis and is adapted to be screwed into an internal thread in a carrierpart, and having an additional thread to be connected to another memberto secure the latter to the carrier part through the medium of saidbody; said body containing a groove extending generally axially throughand interrupting at least a portion of said external thread; a keyhaving a first portion tightly retained in fixed position within anundercut portion of said groove, to remain in said fixed position assaid body is screwed into a carrier part, and adapted to be driventhereafter generally axially to a locking position; said first portionof the key being carried in the groove at a location deep enough toadvance within the interior of said internal thread in the carrier partwithout substantial interference therewith as said body and the carriedkey are screwed into the carrier part, said key having a second portionprojecting axially outwardly beyond the groove and accessible fordriving the key axially inwardly to said locking position after the bodyand key have been screwed into said carrier part; and said groove beingshaped to direct said first portion of the key radially outwardly intosaid internal thread of the carrier part as the key is driven generallyaxially to said locking position and in a relation deforming theinternal thread and locking said body against detachment from thecarrier part, said groove being disposed at an angle to saiD axis, saidfirst portion of the key received within the groove being disposed atsaid angle to the axis, and said second portion which projects axiallyoutwardly beyond the groove being disposed substantially parallel tosaid axis.
 6. A fastener assembly comprising a body having an externalthread which is disposed about an axis and is adapted to be screwed intoan internal thread in a carrier part, and having an additional thread tobe connected to another member to secure the latter to the carrier partthrough the medium of said body; said body containing a groove extendinggenerally axially through and interrupting at least a portion of saidexternal thread; a key having a first portion tightly retained in fixedposition within an undercut portion of said groove, to remain in saidfixed position as said body is screwed into a carrier part, and adaptedto be driven thereafter generally axially to a locking position; saidfirst portion of the key being carried in the groove at a location deepenough to advance within the interior of said internal thread in thecarrier part without substantial interference therewith as said body andthe carried key are screwed into the carrier part, said key having asecond portion projecting axially outwardly beyond the groove andaccessible for driving the key axially inwardly to said locking positionafter the body and key have been screwed into said carrier part; andsaid groove being shaped to direct said first portion of the keyradially outwardly into said internal thread of the carrier part as thekey is driven generally axially to said locking position and in arelation deforming the internal thread and locking said body againstdetachment from the carrier part, said key being shaped to deform thegroove from a non-undercut cross section to an undercut cross section asthe key is driven generally axially, and having a camming shape tendingto urge the key radially against an inner wall of the groove during andas a result of said generally axial movement.
 7. A fastener assemblycomprising a body having an external thread which is disposed about anaxis and is adapted to be screwed into an internal thread in a carrierpart, and having an additional thread to be connected to another memberto secure the latter to the carrier part through the medium of saidbody; said body containing a groove extending generally axially throughand interrupting at least a portion of said external thread; a keyhaving a first portion tightly retained in fixed position within saidgroove, to remain in said fixed position as said body is screwed into acarrier part, and adapted to be driven thereafter generally axially to alocking position; said first portion of the key being carried in thegroove at a location deep enough to advance within the interior of saidinternal thread in the carrier part without substantial interferencetherewith as said body and the carried key are screwed into the carrierpart, said key having a second portion projecting axially outwardlybeyond the groove and accessible for driving the key axially inwardly tosaid locking position after the body and key have been screwed into saidcarrier part; and said groove being shaped to direct said first portionof the key radially outwardly into said internal thread of the carrierpart as the key is driven generally axially to said locking position andin a relation deforming the internal thread and locking said bodyagainst detachment from the carrier part, said groove having a firstportion of undercut cross section containing said key and retaining itagainst radial separation from the groove, and having a second portionof non-undercut cross section beyond said first portion of the grooveand adapted to be deformed to an undercut cross section by the key as itis driven generally axially.
 8. A fastener assembly as recited in claim7, in which said key has fins at its opposite sides for deforming saidgroove to said undercut cross section, said fins having a camming shapetendinG to urge said key tightly against an inner wall of the groove asthe key advances generally axially.
 9. A fastener assembly as recited inclaim 7, in which said groove has a radially inner wall against whichsaid key is received and which in advancing axially inwardly firstextends substantially directly axially at a location spaced inwardly ofthe minor diameter of said external thread and then curves smoothly andgradually radially outwardly to deflect the key into said thread of thecarrier part.
 10. A fastener assembly as recited in claim 7, in whichsaid groove is disposed at an angle to said axis to direct the key at aradially outward angle; said first portion of the key which is retainedin fixed position within said groove, being disposed at said angle tothe axis.
 11. A fastener assembly as recited in claim 7, in which saidgroove, in extending axially inwardly, first extends substantiallydirectly axially and then curves to advance radially toward saidmaterial of the coacting part, said key being constructed to bend infollowing said curving groove.
 12. A fastener assembly as recited inclaim 7, in which said groove is substantially straight and disposed atan angle to said axis.